Upgrade nativemodule samples to 0.76 (#1001)

## Description
Upgrades cppwinrt and csharp samples to 0.76. cpp-lib sample is already
on 0.76 and does not need to be upgraded yet.

### Why
Part of the 0.76 release.
###### Microsoft Reviewers: [Open in
CodeFlow](https://microsoft.github.io/open-pr/?codeflow=https://github.com/microsoft/react-native-windows-samples/pull/1001)

samples/NativeModuleSample/README.md

@@ -2,7 +2,7 @@
 
 These samples showcase building Native Modules for React Native for Windows. It includes implementations in [C#](./csharp/) and [C++/WinRT](./cppwinrt/).
 
-Both implementations target React Native Windows 0.75.
+Both implementations target React Native Windows 0.76.
 
 The official documentation can be found here:
 

samples/NativeModuleSample/cppwinrt/package.json

@@ -5,7 +5,7 @@
   "scripts": {
     "test": "echo \"Error: no test specified\" && exit 1",
     "codegen-windows": "react-native codegen-windows",
-    "windows": "react-native run-windows"
+    "windows": "npx @react-native-community/cli run-windows"
   },
   "peerDependencies": {
     "react": "^16.13.1",
@@ -15,8 +15,8 @@
   "devDependencies": {
     "metro-config": "^0.66.2",
     "react": "18.3.1",
-    "react-native": "0.75.1",
-    "react-native-windows": "^0.75.0"
+    "react-native": "0.76.2",
+    "react-native-windows": "^0.76.2"
   },
   "codegenConfig": {
     "name": "NativeModuleSample",
@@ -25,5 +25,12 @@
     "windows": {
       "namespace": "NativeModuleSample"
     }
+  },
+  "react-native-windows": {
+    "init-windows": {
+      "name": "NativeModuleSample",
+      "namespace": "NativeModuleSample",
+      "template": "old/uwp-cpp-lib"
+    }
   }
 }

samples/NativeModuleSample/cppwinrt/windows/ExperimentalFeatures.props

@@ -16,14 +16,6 @@
     -->
     <UseHermes>true</UseHermes>
 
-    <!--
-      Changes compilation to assume use of WinUI 3 instead of System XAML.
-      Requires creation of new project.
-
-      See https://microsoft.github.io/react-native-windows/docs/winui3
-    -->
-    <UseWinUI3>false</UseWinUI3>
-
     <!--
       Changes compilation to assume use of Microsoft.ReactNative NuGet packages
       instead of building the framework from source.

samples/NativeModuleSample/cppwinrt/windows/NativeModuleSample/NativeModuleSample.vcxproj

@@ -1,5 +1,5 @@
 <?xml version="1.0" encoding="utf-8"?>
-<!-- This project was created with react-native-windows 0.75.0 -->
+<!-- This project was created with react-native-windows 0.76.2 -->
 <Project ToolsVersion="Current" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
   <Import Project="$(SolutionDir)\ExperimentalFeatures.props" Condition="Exists('$(SolutionDir)\ExperimentalFeatures.props')" />
   <PropertyGroup Label="Globals">